Both chronic and acute foot pain affect numerous people. The pain is often caused by one or more of the following conditions: inflammation, decreased blood flow, muscle strain, muscle tension or muscle fatigue. Relief from foot pain can often be obtained by massaging the bottom of the feet and/or by applying either heat or cold to the bottom of the feet.
The rolling of the foot over a tennis ball or a golf ball has been recommended as a massage therapy to treat plantar fascitis, an acute inflammation of the band of tissue that supports the arch. It has even been recommended to place the golf ball in the freezer prior to use (https://www.runningtimes.com/issues/02apr/pf.htm). Golf balls, however, tend to slip out from under the foot during the massage because of their light weight. Also when one attempts to roll a golf ball from the arch to the ball of the foot, it tends to slide out from under the foot unless the user releases pressure on the ball. This disadvantageously causes the user to lose the massage effect. Tennis balls are also too large are deformable—they compress and lose their shape under the pressure of the foot—and thus do not provide an optimal foot massage. Also, the fuzz on the surface of a tennis ball can cause discomfort, as well as shed during use. Moreover, neither golf balls or tennis balls hold cold or warm temperatures for a time sufficient to perform an effective massage.
Numerous foot massage devices are known in the art. U.S. Pat. No. 4,010,743 describes a foot massager composed of a frame which fits parallel rods, wherein each rod contains multiple beads. The user manually rolls the foot over the beads to provide the massage. U.S. Pat. Nos. 4,198,962 and 4,347,838 describe a similar apparatus where multiple rotatable balls are mounted on parallel bars and form a convex surface over which the user rubs the foot. The device may also be associated with an electrically driven vibrator. Products such as these are commercially available as the Wooden Foot Massager (www.lazycomfort.com/woodfootmas.html).
Another type of foot massager is described in U.S. Pat. No. 4,329,981. This device is a mat comprising a plurality of hill-like protuberance over and on top of which the user steps. A somewhat related device is described in U.S. Pat. No. 5,056,507. This device is a combined foot support/massager wherein the user places both feet on an inclined surface containing flexible nipples that contact the toe, sole and heel. The user may provide pressure onto the nippled surface to obtain a massage. The device optionally may contain a heating device within the base supporting the nippled, inclined surface. Rubber nipples contacting the bottom of the foot also provide the massaging action in the device described in U.S. Pat. No. 4,807,602. This device further comprises an electric motor which moves a plate upon which the nipples are mounted. The device further comprises pulsating spray nozzles and a heater which spray the bottom of the users feet with warm water under a variable amount of pressure providing additional massage action and the added benefit of heat.
U.S. Pat. No. 4,446,855 describes a vibrator plate and associated heating element combined with foot-shaped recesses into which the user places the feet for a massage combined with heat.
A massager composed of a cylindrical rod containing protrusions and connected on either end to rollers is described in U.S. Pat. No. 5,411,470. Products such as these are sold as the Accu-Flex Foot Massager and the Footsie Foot Massager (see www.lazycomfort.com/footfootmas.html and www.lazycomfort.com/acfootmas.html). A product known as the Hot and Cold Foot Massager is simply a ridged cylinder divided into two hollow compartments that may be independently filled with cold and hot water (Walter Drake, item #14933) thus providing heat or cold in addition to the massage.
The use of balls to provide foot massage are also known in the art. U.S. Pat. No. 5,785,668 describes an electronic device that simultaneously provides both a vibrating massage and a kneading massage to a body part, where the kneading massage is performed by balls in the device. U.S. Pat. No. 5,605,533 discloses a touch activated foot massager where the bottom of the foot contacts a plurality of rubber balls that driven by a motor vibrate and move, thus providing the massage. PCT Publication No. WO 00/66065 discloses a massage plate with ball holes and balls in the holes. The user rolls his feet over the balls to provide the massage.
Manual ball massagers are also known. U.S. Pat. No. 5,868,689 describes a ball on a flexible cord in between two handles allowing the user to grasp the handles and place the ball between the area of the body to be massaged and a wall, floor or chair. United States Patent Publication No. US 2003/0009118 discloses a rubber massage ball with protrusions attached to a handle strap for providing a massage to various body parts. The Altus Foot Massage and Balance Ball (www.mcsports.com; item#1283592) is a rubber ball or half ball with protrusions. A spongy, soft rubber massage ball having a tacky surface, called a Prana Ball, is said to be able to be warmed or chilled and then used for massage on various parts of the body, including the foot (http://info.product-finder.net/myss/Medium+Thermal+Massage+Ball.html). However, rubber balls and balls made out of other materials that deform easily when pressure is applied to them and thus do not provide sufficient resistance against the foot to give an effective massage. Moreover, the Prana Ball does not appear to be able to retain heat or cold for a sufficient period for an effective massage.
Despite the various massagers on the market, many are not optimally designed for the foot. Those that are designed principally to massage the foot are either not portable, not capable of being heated, cooled or both, require filling with water and thus are prone to leakage or spillage, or require time and space to set up before use. Thus, there still exists a need for a portable, relatively light-weight foot massage apparatus that can be easily heated or cooled and will retain that heat or cold for a time sufficient to administer a massage.